BOOTSSince the robe covers up most of the item you could probably get away with most any black or grey set of feet. However, if you are looking for specific items from Ulduar you have a few choices as well.

Savior's Slippers are from tailoring. The pattern to make it is BoE and drops from Ulduar bosses.

Comment by snub999

Here's a link showing this set with the LFR shoulders. I think the color scheme matches beautifully and its perfect if you like this tier but want shoulders a little less busy (Not to mention the LFR version is easier to come across than clearing 25-man Ulduar). The token for the shoulders isn't sold by the vendor like the chest and helm.